ON THE FORMATION OF THE TAILS OF COMETS. 
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escaped the notice of astronomers. It is a problem reserved for 
a comparatively near future. 
It is exerted also upon our planet at the boundaries of our 
atmosphere, but its meteorological effects are masked by those 
of solar radiation, which is much more powerful, and the period 
of which is exactly the same. I have at least endeavoured to 
demonstrate its presence around us by the action of incandescent 
laminae upon very rariiied matter, which I rendered visible by 
means of electrical currents. In this great difficulties are met 
with, which will not surprise any one who considers the trouble 
it has taken to compel even attraction to manifest itself about 
us between neighbouring bodies. 
***** 
In conclusion, I would indicate that the simultaneous 
existence of several tails, with very different curvatures, is one 
of the most striking verifications of the characters above assigned 
to the repulsive force. These multiple tails are not exceptional 
as was formerly supposed ; their presence is a fact which tends 
to become generalized as comets are observed with very powerful 
instruments. It is true that the present comet seems to have 
only one, but this is no doubt due to our being at no great 
distance from the plane of the orbit, the plane in which all the 
tails are formed, so that, so far as we are concerned, they are 
projected one upon the other. It is for the same reason that 
the tail of the present comet is apparently straight. If instead 
of seeing it edgewise we saw in face, its natural curvature would 
strike all eyes. 
